dotnet/runtime · error · Exception

unknown level {level}

Error message

unknown level {level}

What it means

Raised by convertToLevelId() in genEventing.py when an event's 'level' attribute doesn't match any of the six recognized ETW severity levels. The recognized levels are: win:LogAlways (0), win:Critical (1), win:Error (2), win:Warning (3), win:Informational (4), win:Verbose (5). Any other level string causes the exception.

Source

Thrown at src/coreclr/scripts/genEventing.py:748

            allTemplates  = parseTemplateNodes(templateNodes)
            eventNodes = providerNode.getElementsByTagName('event')
            #pal: create etmdummy.h
            Clretwdummy.write(generateclrEtwDummy(eventNodes, allTemplates) + "\n")

def convertToLevelId(level):
    if level == "win:LogAlways":
       return 0
    if level == "win:Critical":
       return 1
    if level == "win:Error":
       return 2
    if level == "win:Warning":
       return 3
    if level == "win:Informational":
       return 4
    if level == "win:Verbose":
       return 5
    raise Exception("unknown level " + level)

def getKeywordsMaskCombined(keywords, keywordsToMask):
    mask = 0
    for keyword in keywords.split(" "):
       if keyword == "":
          continue
       mask |= keywordsToMask[keyword]

    return mask

def updateclreventsfile(write_xplatheader, target_cpp, runtimeFlavor, is_host_windows, eventpipe_trace_context_typedef, dotnet_trace_context_typedef_windows, tree, clrallevents, inclusion_list, generatedFileType):
    with open_for_update(clrallevents) as Clrallevents:
        Clrallevents.write(stdprolog)
        Clrallevents.write('#include <minipal/guid.h>\n\n')
        if generatedFileType=="header-impl":
            if runtimeFlavor.mono:
                Clrallevents.write(getCoreCLRMonoNativeAotTypeAdaptionDefines() + "\n")
            if runtimeFlavor.coreclr or write_xplatheader:

View on GitHub (pinned to 60108ba66e)

Solutions

1. Check the 'level' attribute on the event element identified in the manifest.
2. Use one of the exact strings: win:LogAlways, win:Critical, win:Error, win:Warning, win:Informational, win:Verbose.
3. If a custom level is needed, add a mapping for it in convertToLevelId().
4. Ensure the 'win:' prefix is present on standard level names.

Example fix

<!-- before: incorrect level name -->
<event symbol="MyEvent" value="1" level="win:Info" template="t:MyEvent" />

<!-- after: correct level name -->
<event symbol="MyEvent" value="1" level="win:Informational" template="t:MyEvent" />

VALID_LEVELS = frozenset([
    'win:LogAlways', 'win:Critical', 'win:Error',
    'win:Warning', 'win:Informational', 'win:Verbose'
])

def validate_event_levels(manifest_path: str) -> list:
    """Return list of events with unrecognized level values."""
    import xml.dom.minidom as DOM
    tree = DOM.parse(manifest_path)
    issues = []
    for event in tree.getElementsByTagName('event'):
        level = event.getAttribute('level')
        symbol = event.getAttribute('symbol')
        if level not in VALID_LEVELS:
            issues.append(f"Event '{symbol}' has invalid level '{level}'. Valid: {sorted(VALID_LEVELS)}")
    return issues

null

try:
    level_id = convertToLevelId(levelName)
except Exception as e:
    if 'unknown level' in str(e):
        print(f"Invalid event level: {e}")
        print(f"Use one of: {sorted(VALID_LEVELS)}")
    raise

When it happens

Trigger: Triggered when convertToLevelId(levelName) is called (from the clrproviders.h generation loop at line 943 where levelName = eventNode.getAttribute('level')) and the value doesn't match any of the if-conditions. This happens for typos, non-standard level names, or custom levels defined via <level> elements in the manifest that aren't in the standard set.

Common situations: A developer types 'win:Info' instead of 'win:Informational', or 'win:Fatal' instead of 'win:Critical'. A manifest uses a custom level name defined in a <level> element that the code generator doesn't map. An XML namespace prefix is missing or different (e.g., 'Informational' without the 'win:' prefix).

Related errors

• {}:No ClrInstanceID field of type win:UInt16 for event symbo
• both count and length property found on: {variable}in templa
• {}: Error processing event :{}(ID{}): This file must contain
• Don't know size for {}
• unknown attribute: {} in template:{}

AI-assisted analysis of dotnet/runtime@60108ba66e (2026-08-10). Data as JSON: /api/errors/7969ea365daad91b. Report an issue: GitHub.